This invention relates to oscillator circuits, and more specifically to oscillator circuits suitable for use in integrated circuits.
Oscillator circuits find many applications, particularly in the areas of timing circuits and clock signal generators. It is well known in the art to utilize an oscillator as a clock signal generator, and to set the frequency to be generated by use of a timing capacitor. The time constant of capacitor charge or discharge can be conveniently calculated and provides a basis for approximating the desired frequency in a clock circuit. Examples of the utilization of a timing capacitor in an oscillator circuit may be seen in U.S. Pat. No. 3,934,233, (FIG. 6Q) and on pages 285-287 of "The Linear Control Circuits Data book for Design Engineers," Second Edition, Texas Instruments Incorporated, Dallas, Texas. Typically, prior art circuits utilized the supply voltages to charge and discharge the timing capacitor.